1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
|
/* Auxiliary functions for the creation of subprocesses. Native Woe32 API.
Copyright (C) 2003, 2006-2008 Free Software Foundation, Inc.
Written by Bruno Haible <bruno@clisp.org>, 2003.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
/* Get declarations of the Win32 API functions. */
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
/* Get _get_osfhandle() and _open_osfhandle(). */
#include <io.h>
#include <stdbool.h>
#include <string.h>
#include <errno.h>
#include "xalloc.h"
/* Duplicates a file handle, making the copy uninheritable. */
static int
dup_noinherit (int fd)
{
HANDLE curr_process = GetCurrentProcess ();
HANDLE old_handle = (HANDLE) _get_osfhandle (fd);
HANDLE new_handle;
int nfd;
if (!DuplicateHandle (curr_process, /* SourceProcessHandle */
old_handle, /* SourceHandle */
curr_process, /* TargetProcessHandle */
(PHANDLE) &new_handle, /* TargetHandle */
(DWORD) 0, /* DesiredAccess */
FALSE, /* InheritHandle */
DUPLICATE_SAME_ACCESS)) /* Options */
error (EXIT_FAILURE, 0, _("DuplicateHandle failed with error code 0x%08x"),
GetLastError ());
nfd = _open_osfhandle ((long) new_handle, O_BINARY);
if (nfd < 0)
error (EXIT_FAILURE, errno, _("_open_osfhandle failed"));
return nfd;
}
/* Prepares an argument vector before calling spawn().
Note that spawn() does not by itself call the command interpreter
(getenv ("COMSPEC") != NULL ? getenv ("COMSPEC") :
({ OSVERSIONINFO v; v.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
GetVersionEx(&v);
v.dwPlatformId == VER_PLATFORM_WIN32_NT;
}) ? "cmd.exe" : "command.com").
Instead it simply concatenates the arguments, separated by ' ', and calls
CreateProcess(). We must quote the arguments since Win32 CreateProcess()
interprets characters like ' ', '\t', '\\', '"' (but not '<' and '>') in a
special way:
- Space and tab are interpreted as delimiters. They are not treated as
delimiters if they are surrounded by double quotes: "...".
- Unescaped double quotes are removed from the input. Their only effect is
that within double quotes, space and tab are treated like normal
characters.
- Backslashes not followed by double quotes are not special.
- But 2*n+1 backslashes followed by a double quote become
n backslashes followed by a double quote (n >= 0):
\" -> "
\\\" -> \"
\\\\\" -> \\"
*/
#define SHELL_SPECIAL_CHARS "\"\\ \001\002\003\004\005\006\007\010\011\012\013\014\015\016\017\020\021\022\023\024\025\026\027\030\031\032\033\034\035\036\037"
#define SHELL_SPACE_CHARS " \001\002\003\004\005\006\007\010\011\012\013\014\015\016\017\020\021\022\023\024\025\026\027\030\031\032\033\034\035\036\037"
static char **
prepare_spawn (char **argv)
{
size_t argc;
char **new_argv;
size_t i;
/* Count number of arguments. */
for (argc = 0; argv[argc] != NULL; argc++)
;
/* Allocate new argument vector. */
new_argv = XNMALLOC (1 + argc + 1, char *);
/* Add an element upfront that can be used when argv[0] turns out to be a
script, not a program.
On Unix, this would be "/bin/sh". On native Windows, "sh" is actually
"sh.exe". We have to omit the directory part and rely on the search in
PATH, because the mingw "mount points" are not visible inside Win32
CreateProcess(). */
*new_argv++ = "sh.exe";
/* Put quoted arguments into the new argument vector. */
for (i = 0; i < argc; i++)
{
const char *string = argv[i];
if (string[0] == '\0')
new_argv[i] = xstrdup ("\"\"");
else if (strpbrk (string, SHELL_SPECIAL_CHARS) != NULL)
{
bool quote_around = (strpbrk (string, SHELL_SPACE_CHARS) != NULL);
size_t length;
unsigned int backslashes;
const char *s;
char *quoted_string;
char *p;
length = 0;
backslashes = 0;
if (quote_around)
length++;
for (s = string; *s != '\0'; s++)
{
char c = *s;
if (c == '"')
length += backslashes + 1;
length++;
if (c == '\\')
backslashes++;
else
backslashes = 0;
}
if (quote_around)
length += backslashes + 1;
quoted_string = (char *) xmalloc (length + 1);
p = quoted_string;
backslashes = 0;
if (quote_around)
*p++ = '"';
for (s = string; *s != '\0'; s++)
{
char c = *s;
if (c == '"')
{
unsigned int j;
for (j = backslashes + 1; j > 0; j--)
*p++ = '\\';
}
*p++ = c;
if (c == '\\')
backslashes++;
else
backslashes = 0;
}
if (quote_around)
{
unsigned int j;
for (j = backslashes; j > 0; j--)
*p++ = '\\';
*p++ = '"';
}
*p = '\0';
new_argv[i] = quoted_string;
}
else
new_argv[i] = (char *) string;
}
new_argv[argc] = NULL;
return new_argv;
}
|
